Node Explorer: follow symbolic links to directories

src/filesystem-provider-sftp.ts

@@ -66,8 +66,9 @@ export class FileSystemProviderSFTP implements vscode.FileSystemProvider {
     const deleteRecursively = async (path: string) => {
       const st = await sftp.stat(path);
 
-      // short circuit for files
-      if (st.type === vscode.FileType.File) {
+      // short circuit for files and symlinks
+      // (don't recursively delete through symlinks that point to directories)
+      if (st.type & vscode.FileType.File || st.type & vscode.FileType.SymbolicLink) {
         await sftp.delete(path);
         return;
       }
@@ -77,7 +78,7 @@ export class FileSystemProviderSFTP implements vscode.FileSystemProvider {
       for (const [file, fileType] of files) {
         const filePath = `${path}/${file}`;
 
-        if (fileType === vscode.FileType.Directory) {
+        if (fileType & vscode.FileType.Directory) {
           await deleteRecursively(filePath);
         } else {
           await sftp.delete(filePath);

src/filesystem-provider.ts

@@ -10,10 +10,10 @@ export interface FileSystemProvider extends vscode.FileSystemProvider {
 // fileSorter mimicks the Node Explorer file structure in that directories
 // are displayed first in alphabetical followed by files in the same fashion.
 export function fileSorter(a: [string, vscode.FileType], b: [string, vscode.FileType]): number {
-  if (a[1] === vscode.FileType.Directory && b[1] !== vscode.FileType.Directory) {
+  if (a[1] & vscode.FileType.Directory && !(b[1] & vscode.FileType.Directory)) {
     return -1;
   }
-  if (a[1] !== vscode.FileType.Directory && b[1] === vscode.FileType.Directory) {
+  if (!(a[1] & vscode.FileType.Directory) && b[1] & vscode.FileType.Directory) {
     return 1;
   }
 

src/node-explorer-provider.ts

@@ -312,14 +312,14 @@ export class NodeExplorerProvider
    */
   refresh(target?: FileExplorer | FileExplorer[]) {
     if (Array.isArray(target)) {
-      if (target.every((item) => item.type === vscode.FileType.Directory)) {
+      if (target.every((item) => item.type & vscode.FileType.Directory)) {
         for (const item of target) {
           this._onDidChangeTreeData.fire([item]);
         }
       } else {
         this._onDidChangeTreeData.fire(undefined);
       }
-    } else if (target && target.type === vscode.FileType.Directory) {
+    } else if (target && target.type & vscode.FileType.Directory) {
       // If 'target' is a single object
       this._onDidChangeTreeData.fire([target]);
     } else {
@@ -514,9 +514,13 @@ export class NodeExplorerProvider
   registerDeleteCommand() {
     vscode.commands.registerCommand('tailscale.node.fs.delete', async (file: FileExplorer) => {
       try {
-        const msg = `Are you sure you want to delete ${
-          file.type === vscode.FileType.Directory ? 'this directory' : 'this file'
-        }? This action cannot be undone.`;
+        let fileDescription = 'file';
+        if (file.type & vscode.FileType.SymbolicLink) {
+          fileDescription = 'symbolic link';
+        } else if (file.type & vscode.FileType.Directory) {
+          fileDescription = 'directory';
+        }
+        const msg = `Are you sure you want to delete this ${fileDescription}? This action cannot be undone.`;
 
         const answer = await vscode.window.showInformationMessage(msg, { modal: true }, 'Yes');
 
@@ -552,7 +556,7 @@ export class NodeExplorerProvider
         return;
       }
 
-      if (node.type !== vscode.FileType.Directory) {
+      if (!(node.type & vscode.FileType.Directory)) {
         targetPath = path.dirname(resourcePath);
       }
 
@@ -565,7 +569,7 @@ export class NodeExplorerProvider
       try {
         await vscode.workspace.fs.writeFile(newUri, new Uint8Array());
         this._onDidChangeTreeData.fire([
-          node.type !== vscode.FileType.Directory ? undefined : node,
+          !(node.type & vscode.FileType.Directory) ? undefined : node,
         ]);
       } catch (e) {
         vscode.window.showErrorMessage(`Could not create directory: ${e}`);
@@ -618,7 +622,7 @@ export class NodeExplorerProvider
           return;
         }
 
-        if (node.type !== vscode.FileType.Directory) {
+        if (!(node.type & vscode.FileType.Directory)) {
           const lastSlashIndex = resourcePath.lastIndexOf('/');
           targetPath = resourcePath.substring(0, lastSlashIndex);
         }
@@ -632,7 +636,7 @@ export class NodeExplorerProvider
         try {
           await vscode.workspace.fs.createDirectory(newUri);
           this._onDidChangeTreeData.fire([
-            node.type !== vscode.FileType.Directory ? undefined : node,
+            !(node.type & vscode.FileType.Directory) ? undefined : node,
           ]);
         } catch (e) {
           vscode.window.showErrorMessage(`Could not create directory: ${e}`);
@@ -777,29 +781,29 @@ export class FileExplorer extends vscode.TreeItem {
     public readonly uri: vscode.Uri,
     public readonly type: vscode.FileType,
     public readonly context?: string,
-    public readonly collapsibleState: vscode.TreeItemCollapsibleState = type ===
+    public readonly collapsibleState: vscode.TreeItemCollapsibleState = type &
     vscode.FileType.Directory
       ? vscode.TreeItemCollapsibleState.Collapsed
       : vscode.TreeItemCollapsibleState.None,
     public readonly description: string = ''
   ) {
     super(label, collapsibleState);
 
-    if (type === vscode.FileType.File || vscode.FileType.SymbolicLink) {
+    if (type & vscode.FileType.File) {
       this.command = {
         command: 'vscode.open',
         title: 'Open File',
         arguments: [this.uri],
       };
     }
 
-    const typeDesc = type === vscode.FileType.File ? 'file' : 'dir';
+    const typeDesc = type & vscode.FileType.File ? 'file' : 'dir';
     this.contextValue = `peer-file-explorer-${typeDesc}${context ? `-${context}` : ''}`;
   }
 
   getDirectory(fileName?: string): vscode.Uri {
     let resourcePath = this.uri.toString();
-    if (this.type !== vscode.FileType.Directory) {
+    if (!(this.type & vscode.FileType.Directory)) {
       const lastSlashIndex = resourcePath.lastIndexOf('/');
       resourcePath = resourcePath.substring(0, lastSlashIndex);
     }

src/sftp.ts

@@ -1,3 +1,4 @@
+import * as path from 'path';
 import * as ssh2 from 'ssh2';
 import * as util from 'util';
 import * as vscode from 'vscode';
@@ -13,13 +14,29 @@ export class Sftp {
     return this.sftpPromise;
   }
 
+  async readSymbolicLink(linkPath: string): Promise<string> {
+    const sftp = await this.getSftp();
+    let result = await util.promisify(sftp.readlink).call(sftp, linkPath);
+
+    // if link is relative, not absolute
+    if (!result.startsWith('/')) {
+      // note: this needs to be / even on Windows, so don't use path.join()
+      result = `${path.dirname(linkPath)}/${result}`;
+    }
+
+    return result;
+  }
+
   async readDirectory(path: string): Promise<[string, vscode.FileType][]> {
     const sftp = await this.getSftp();
     const files = await util.promisify(sftp.readdir).call(sftp, path);
     const result: [string, vscode.FileType][] = [];
 
     for (const file of files) {
-      result.push([file.filename, this.convertFileType(file.attrs as ssh2.Stats)]);
+      result.push([
+        file.filename,
+        await this.convertFileType(file.attrs as ssh2.Stats, `${path}/${file.filename}`),
+      ]);
     }
 
     return result;
@@ -32,10 +49,19 @@ export class Sftp {
 
   async stat(path: string): Promise<vscode.FileStat> {
     const sftp = await this.getSftp();
-    const s = await util.promisify(sftp.stat).call(sftp, path);
+    // sftp.lstat, when stat-ing symlinks, will stat the links themselves
+    // instead of following them. it's necessary to do this and then follow
+    // the symlinks manually in convertFileType since file.attrs from sftp.readdir
+    // returns a Stats object that claims to be a symbolic link, but neither a
+    // file nor a directory. so convertFileType needs to follow symlinks manually
+    // to figure out whether they point to a file or directory and correctly
+    // populate the vscode.FileType bitfield. this also allows symlinks to directories
+    // to not accidentally be treated as directories themselves, so deleting a symlink
+    // doesn't delete the contents of the directory it points to.
+    const s = await util.promisify(sftp.lstat).call(sftp, path);
 
     return {
-      type: this.convertFileType(s),
+      type: await this.convertFileType(s, path),
       ctime: s.atime,
       mtime: s.mtime,
       size: s.size,
@@ -83,13 +109,16 @@ export class Sftp {
     return util.promisify(sftp.fastPut).call(sftp, localPath, remotePath);
   }
 
-  convertFileType(stats: ssh2.Stats): vscode.FileType {
+  async convertFileType(stats: ssh2.Stats, filename: string): Promise<vscode.FileType> {
     if (stats.isDirectory()) {
       return vscode.FileType.Directory;
     } else if (stats.isFile()) {
       return vscode.FileType.File;
     } else if (stats.isSymbolicLink()) {
-      return vscode.FileType.SymbolicLink;
+      const sftp = await this.getSftp();
+      const target = await this.readSymbolicLink(filename);
+      const tStat = await util.promisify(sftp.stat).call(sftp, target);
+      return vscode.FileType.SymbolicLink | (await this.convertFileType(tStat, target));
     } else {
       return vscode.FileType.Unknown;
     }